Most local businesses miss between a quarter and a third of their inbound calls. The caller is usually a customer with a credit card out, and most of them do not leave a voicemail; they call the next business in the search results. Because a missed call makes no noise, nobody adds it up. The free Missed Call Revenue Calculator does the sum in a few seconds. This guide explains the formula, where to find your own numbers and what to do with the answer.
The formula
Monthly calls multiplied by missed-call rate gives missed calls per month. Missed calls multiplied by close rate gives customers lost per month. Customers lost multiplied by average customer value gives revenue lost per month, and twelve times that is the annual figure. The calculator then applies a recovery rate to estimate how much of that revenue a system that answers every call would win back.
Step 1: Choose your industry
Pick your industry from the list and the calculator pre-fills a typical average customer value: around $3,000 for home services, $4,500 for HVAC, $9,000 for roofing, $900 for a dental practice, $3,500 for a law firm, $1,200 for a med spa, $650 for auto repair, $200 for a salon. These are planning averages. Override them with your own number in the next step.
Step 2: Enter your average customer value
Use the lifetime value of a new customer, not the first ticket, if customers come back. A dental patient is worth far more than one cleaning; an HVAC customer is worth the install plus years of service calls. If you do not know, take last year’s revenue and divide by the number of new customers.
Step 3: Enter your monthly inbound calls
Your phone system or your call tracking tool has this number. If you have neither, count for one typical week and multiply by four and a third. Include after-hours and weekend calls, because those are the ones most likely to be missed.
Step 4: Set the assumptions
The calculator defaults to a 27 percent missed-call rate, a 35 percent close rate on the calls you do answer, and a 90 percent recovery rate for a system that answers everything. Open the advanced settings and change any of them. If you have a call log that shows how many calls went to voicemail, use the real missed-call rate; it is usually higher than owners expect. Your close rate is bookings divided by answered calls. The recovery rate depends on the fix you choose, which is covered below.
Step 5: Read the result
You get missed calls per month, lost customers per month, lost revenue per month and per year, and the recoverable annual revenue. For a roofing company taking 150 calls a month at the default assumptions, that is about 40 missed calls and 14 lost customers a month, around $127,000 in lost revenue every month and more than $1.5 million a year. Enter your name and email to receive the breakdown.
Four ways to stop missing calls, compared
Hire more front-desk staff
Works during business hours, costs a salary per seat, does nothing for evenings and weekends, and still misses calls when two come in at once.
A traditional answering service
Answers after hours but reads from a card. Most cannot book an appointment, answer a real question or qualify a lead, so the caller still has to wait for a callback, and many do not.
Text back missed callers
An automatic "sorry we missed you" text recovers some callers cheaply, and it is better than nothing. It still depends on the caller replying and on someone following up quickly.
A 24/7 AI voice agent
Answers every call on the first ring, at any hour, in a natural voice. Answers questions from your knowledge base, qualifies the caller, books the appointment onto your calendar and texts a confirmation. This is the option the 90 percent recovery default assumes, and it is what our customer service AI does.
Step 6: Fix the downstream damage too
Missed calls do not only cost the sale. The callers who are annoyed enough leave reviews, and "nobody answers the phone" is one of the most common complaints in one-star reviews of service businesses. If you already have a few of those, the AI Review Reply Generator will help you answer them well while you fix the cause.
Run your numbers. Most owners are surprised, and the surprise is the point.
